The inventive concept relates generally to image sensors, image sensing methods, and image photographing apparatuses including image sensor(s). More particularly, the inventive concept relates to image sensors capable of operating with improved signal-to-noise (SNR) ratios under low-illuminance conditions, as well as image sensing methods and image photographing apparatuses including such image sensor(s).
Technology related to imaging devices and image photographing methods is rapidly developing. As pixel size has been reduced, certain binary sensor techniques or multi-bit, over-sampling sensor techniques have become increasingly important in various image acquisition techniques that ensure a full well capacity (FWC) range. Unfortunately, conventional approaches to multi-bit, over-sampling sensor techniques performed under low-illuminance conditions often results in an unacceptable signal-to-noise ratio (SNR).